How can I enable coredump in macos

The following code can cause core dump

#include <cstdio>
int main(){
    printf("%d", *((int*)1));
}

However when I run on my mac, there is no coredump generated in /cores

calvin@CalvinPC test % ./a
zsh: segmentation fault  ./a
calvin@CalvinPC test % ls -a /cores
.   ..

However, I already have ulimit -c unlimited, and sudo sysctl kern.coredump=1

So, how can I cause a core dump in macos?